Self-assembly of Sb2S3 NRs-M (M = Au, Ag, Pd) heterostructures towards boosted photocatalysis†

Abstract

Antimony sulfide (Sb₂S₃) has been deemed a promising semiconductor for solar energy conversion owing to its suitable energy level position. However, so far, Sb₂S₃-based photocatalytic systems have been poorly reported, making Sb₂S₃-dominated photocatalytic mechanisms elusive. Herein, an efficient electrostatic self-assembly strategy was developed to fabricate metal nanocrystal (NC)-functionalized Sb₂S₃ nanorod (Sb₂S₃ NRs-M, M = Au, Ag, Pd) heterostructures. The tartaric acid (TA) molecules grafted on the Sb₂S₃ NR surface served as coordination sites, which enabled the self-assembly of the metal precursor on the Sb₂S₃ NR surface via electrostatic and coordinate interactions. The as-prepared Sb₂S₃ NRs-M (M = Au, Ag, Pd) heterostructures demonstrated significantly enhanced photoactivities toward the mineralization of organic pollutants under visible light irradiation, surpassing those of the pristine Sb₂S₃ NR counterpart. The contributing role of metal NCs as “electron reservoirs” in boosting the charge separation was determined. Furthermore, active species participating in the photocatalytic reaction were determined, and the photocatalytic mechanism was unveiled. This study offers an efficacious strategy for the rational construction of metal NC-functionalized Sb₂S₃ NRs for widespread photocatalytic applications.